Fluent material mixing and dispensing apparatus



Jan. 28, 1969 w. P. VANCE FLUENT MATERIAL MIXING ANfi DISPENSINGAPPARATUS Filed April 5. 1967 w Wm m a m x mm r m l w w 4 w w E A I I868 L IZ/ PRESSURE RELIEF VAL VE fuvswroe. 71/500120! P. Vfl/VCEfl-rralzwss United States Patent 9 Claims ABSTRACT OF THE DISCLOSUREFluid material mixing and dispensing apparatus having a hermetictankwith an upper opening through which a solid ingredient of the materialmay be introduced into the tank, a lower material discharge conduit forconveying the fluid material from the tank to a point of use, means forinitially supplying a liquid ingredient of the material to the tankthrough and subsequently flushing out the discharge conduit, and meansfor supplying compressed gas, such as air, to nozzles within the tankand to the discharge conduit for initially agitating the fluid materialwithin the tank while preventing blocking of the material outlet fromthe tank, and for then simultaneous- 1y agitating the material in andexpelling the material from the tank.

This invention relates generally to fluid handling apparatus. Moreparticularly, the invention relates to apparatus for mixing anddispensing to a point of use fluid materials, such as cementitiousmaterials, paints, and the like.

As will appear from the ensuing description, the present mixing anddispensing apparatus may be utilized to mix and dispense various fluidmaterials, including fluid mixtures of liquid or semi-liquid ingredientsonly, as fluid mixtures of liquid and solid ingredients. Moreover,certain features of the invention may be utilized to advantage inapparatus for mixing and dispensing fluidic mixtures of dry ingredientsonly. For convenience, the expression fluid material is employed in thisdisclosure in its broadest sense to encompass any and all p of thesevarious materials or mixtures.

A great variety of devices have been devised for mixing and, dispensingfluid materials of the character described The existing devices of thiskind, however, are deficientin that they utilize either mechanical meansonly or a combination of mechanical and pneumatic means for agitatingand dispensing a fluid material. Purely mechanical mixing and dispensingdevices, for example, commonly employ motor driven agitators for mixingand motor driven pumps for dispensing. Some of the existing mechanicaland pneumatic mixing and dispensing devices, on the other hand, utilizemotor driven agitators for mixing and a pressurized gas, such as air,for dispensing. Other devices utilize a pressurized gas for agitationand motor driven pumps for dispensing.

These existing mixing and dispensing devices, while satisfactory forsome applications, possess certain deficiencies which the presentinvention seeks to overcome. Thus, the existing devices arecharacterized by undesirable complexity, high cost, large size,excessive weight, and other adverse structural and functionalcharacteristics. Both types of existing devices referred to above, forexample, require motors, shafts, gears, bearings, electrical cables, andnumerous other stationary and movable mechanical elements. In addition,those devices which employ combined mechanical and pneumatic means formixing and dispensing require two separate power sources, to wit, anelectrical power source and a high pressure fluid source, as well asboth electrical cables and air hoses.

3,424,349 Patented Jan. 28, 1969 It is a general object of thisinvention to provide an improved apparatus for mixing and dispensingfluid materials which avoids the above-noted and other deficiencies ofthe prior art devices.

A more specific object of the invention is to provide an improved mixingand dispensing apparatus for the purposes described wherein both themixing and dispensing functons are accomplished pneumatically.

A further object of the invention is to provide an improved mixing anddispensing apparatus for the purpose described which is uniquelyconstructed and arranged to effect continued mixing of the fluidmaterial during dispensing thereof, to prevent blocking of the materialdischarge from the mixing tank during mixing of the fluid material inthe tank, to permit final flushing of the material discharge conduit,and to provide ease and reliability of operation, economy ofmanufacture, and convenience of transportation from one work site toanother.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration of a formin which it may be embodied. This form is shown in the drawingsaccompanying and forming part of the present specification. It will nowbe described in detail, for the purpose of illustrating the generalprinciples of the invention; but it is to be understood that suchdetailed description is not to be taken in a limiting sense, since thescope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is an elevational view of an improved mixing and dispensingapparatus according to the invention, illustrating the mixing tank invertical section;

FIG. 2 is a section taken on line 2-2 in FIG. 1; and

FIG. 3 is an enlarged fragmentary detail, partly in section, of one ofthe nozzles embodied in the pneumatic agitating portion of theapparatus.

According to its broader aspects, the invention provides a mixing anddispensing apparatus, represented in the drawings by the apparatus 10,including a hermetic tank 12 having a chamber 14 for containing a fluentmaterial to be mixed and dispensed and a lower port 16 opening to thechamber. Leading into the tank chamber 14, and connected to apressurized source (not shown) of a gas, such as air, are conduits 18which discharge the pressurized gas into and thereby agitate the fluidmaterial within the chamber. Leading from the lower .port 16 of the tank12 is a material discharge conduit 20 for conveying fluid material fromthe chamber 14 to a point of use. Discharge conduit 20 contains adischarge valve 22 for controlling material flow through the conduit.;Ina typical application of the present mixing and dispensing apparatus,the discharge conduit 20 may include a hose 20a and connect to a spraynozzle (not shown) from which the fluid or fluent material emerges inthe form of a spray. In this case, the discharge valve 22 may beembodied directly in the nozzle. At the upper end of the tank 12 arevent means 24 for selectively communicating the tank chamber 14 toatmosphere. As Will appear from the ensuing description, the presentmixing and dispensing apparatus so so constructed and arranged that,initially, the vent means 24 may be opened, the discharge valve 22closed, and the gas supply conduit means 18 supplied with gas underpressure to eflect agitation of the fluid material within the tankchamber 14. Thereafter, the vent means may be closed, the dischargevalve opened, and the gas supply conduits continued to be supplied withgas under pressure to effect continued agitation of the fluid materialwithin the chamber and simultaneous discharge and delivery of thematerial from the chamber 14 to a point of use through the dischargeconduit 20 and its delivery hose 20a.

As noted earlier, the mixing and dispensing apparatus of the inventionmay be employed to mix and dispense various fluid materials, includingfluid mixtures of liquid ingredients only, fluid mixtures of both liquidand solid ingredients, and fluidic mixtures of solid ingredients only.The particular apparatus illustrated in the drawings is intendedprimarily for mixing and dispensing fluid mixtures of both liquid andsolid ingredients, such as cement and plaster slurries, and the like. Inthis case, the upper vent means 24 of the apparatus may comprise anopening 26 in the upper end of the tank 12, sealed by a removable hatchcover 28, through which the solid ingredient or ingredients of the fluidmaterial may be introduced into the tank chamber 14, and liquid supplymeans 30 for introducing the liquid ingredient or ingredients of thefluid material into the chamber. When the tank of the present mixing anddispensing apparatus is equipped with such a hatch cover, it may bedesirable or necessary to vent the tank chamber 14 at certain times inthe operation of the apparatus to facilitate or permit opening andclosing of the cover with ease and safety. To this end, the vent means24 of the illustrated apparatus also comprise a pressure relief venttube 32 which extends through and is sealed to the wall of the tank 12,so as to communicate the chamber 14 to atmosphere, and contains a manualpressure relief or shutoff valve 36.

In those applications of the present apparatus in which the latter isemployed to mix and dispense fluid mixtures of liquid and solidingredients, it may be desirable or necessary to prevent blocking of thelower tank port 16 by the fluid material, particularly the solidingredients of the material, during mixing. A feature of the inventionin this regard resides in the fact that the gas supply conduit means 18include an external gas supply conduit 38, one end of which is connectedto a source (not shown) of pressurized gas, such as air, and the otherend of which is connected to the fluid material discharge conduit 20between the tank 12 and the discharge valve 22. During mixing operationof the apparatus, the discharge valve may be closed and gas underpressure may be supplied to the tank chamber 14 through the gas supplyconduit 38 and the discharge conduit 20. This gas thus enters thechamber 14 through the lower tank port 16 and thereby prevents this portfrom being blocked by the material in the tank. According to anotherfeature of the invention, the liquid supply means 30 comprise a liquidsupply conduit 40 which contains a liquid supply valve 42 and connectsto the discharge conduit 20 between the tank 12 and the discharge valve22, and the discharge conduit contains a shutoff valve 44 between thetank and the liquid supply conduit. This arrangement of the presentmixing and dispensing apparatus permits initial introduction of a liquidingredient into the tank chamber 14 by closing the discharge valve 22and opening the shutoff valves 42, 44, and final flushing of thedischarge conduit by opening the discharge valve 22 and the liquidsupply valve 42 and closing the shutoff valve 44.

Referring now in greater detail to the embodiment of the invention whichhas been selected for illustration in the drawings, the hermetic tank 12has a generally cylindrical side wall 46 and generally semi-sphericalupper and lower end walls 48 and 50, respectively. These end walls maybe joined to the side wall 46 in any convenient way, as by welding. Inorder to facilitate movement of the tank 12 from one location toanother, the tank is equipped with four depending legs 52 which areshown to comprise metal angles welded to the tank. Mounted on the lowerends of two of the tank legs 52 are rollers or casters 54. The remainingtwo legs of the tank have transverse plates 56 welded to their lowerends. Threaded in these plates are adjustable ground supports or screws58. When the tank 12 is disposed in its normal stationary operativeposition, the casters 54 and the screws 58 rest on the ground. Thescrews are adjustable to level the tank. When it becomes necessary tomove the tank from one location to another, the tank is rotated slightlyabout the casters 54 to elevate the screws 58 out of contact with theground and the tank is then pulled or pushed to effect rolling movementof the casters along the ground.

The upper tank wall 48 has a central opening 60 in which is positionedand welded a cylindrical collar or rim 62. This rim defines the opening26 in the upper end of the tank 12. Welded to the inner surfaces of theupper tank wall 48, about the edge of the wall opening 60, is a ring 64.The inner edge of this ring projects radially inward a distance beyondthe inner surface of the cylindrical rim 62 to define a shoulder forseating a grill 66. Grill 66 has a central solid circular portion 68surrounded by an outer annular perforate portion 70. This perforateportion of the grill may comprise a number of parallel bars which arespaced to define therebetween relatively long and narrow slot-likeopenings. Grill 66 serves the dual function of a support on which a sackof dry ingredient may be rested when pouring the ingredient into thetank chamber 14 and a means for regulating the rate of entrance of thedry ingredient into the chamber and uniformly dispersing the enteringingredient about the interior of the chamber. The grill merely rests onthe shoulder ring 64 and thus may be removed when its use isunnecessary.

The hatch cover 28 has a generally dome-shaped upper wall 72 and adepending rim 74 on the underside of the wall which is externallydimensioned to fit closely within the upper end of the cylindrical tankrim 62 when the cover is closed. Formed in the underside of the coverwall 72 about the rim 74 is an annular groove 76 for receiving the upperedge of the tank rim 62 in the closed position of the hatch cover. Thisgroove contains a seal ring or gasket 78 for providing an airtight jointbetween the cover and tank rim. One side of the hatch cover 28 isattached to the outside of the tank rim 62 by a hinge 80 which permitsthe cover to be rotated between its open and closed positions. At theopposite side of the cover are locking means 82 for releasably lockingthe cover in its closed position. Various locking means may be providedfor this purpose. The illustrated locking means, for example, comprise ascrew shaft 84 which is pivotally attached at its lower end to aprojecting lug 86 on the outside of the tank rim 62 and extends at itsupper end through a slot formed in a projecting flange 88 on the hatchcover 28. A cam 90 is pivotally secured to the upper end of the threadedshaft 84 in such a way that during its rotation to its position of FIG.1, the cam exerts a downward camming force on the cover flange 88 forurging the hatch cover 28 to and retaining the hatch cover in its closedposition. Rotation of the cam in a counterclockwise direction in FIG. 1through approximately provides suflicient clearance between the cam andthe cover flange 88 to enable the threaded shaft 84 to be rotated out ofthe slot in the flange and thereby release the cover for opening.

It is evident at this point that the hatch cover 28 and its associatedstructure just described form part of the vent means 24 on the tank 12.It will be recalled that this vent means further comprises a pressurerelief vent tube 32. This vent tube extends through and is welded to theupper end wall 48 of the tank at one side of the hatch cover. Thepressure relief valve 36 on this tube is exposed above the tank wall 48for manual opening and closing of the valve.

The gas supply conduit means 18 of the illustrated dispensing and mixingapparatus 10 comprise a number, shown to be four, of inner gas supplyconduits 92 which extend vertically through the upper tank wall 48 anddownwardly through the tank chamber 14 adjacent the cylindrical wall 46to positions adjacent the lower tank wall 50. The upper ends of theseconduits are welded to the tank wall 48. The lower ends of the conduits92 are open. The upper external ends of the conduits 92 are connected toa source (not shown) of pressurized gas, such as air.

In a typical mixing and dispensing apparatus according to the invention,for example, the gas source to which are connected the internal gassupply conduits 92, as well as the external gas supply conduit 38:, maycomprise a motor driven air compressor which may be manually controlledto supply air under pressure to or discontinue the supply of air underpressure to the conduits and automatically controlled in response to theair pressure in the tank chamber 14 to maintain a relatively constantpressure in the chamber. In any case, it is evident at this point thatair under pressure, which is supplied to the inner conduits 92, issuesfrom the open lower ends of these conduits.

Mounted on the lower ends of the inner air conduits 92 are deflectors'94, one of which is shown in enlarged sectional detail in FIG. 3. Thesedeflectors have a lower open arcuate trough-like extremity for divertingthe air emerging from the lower ends of the conduits 92 in a generallydownward and tangential direction relative to the tank .12. In thisregard, it will be observed that all of the deflectors 94 are arrangedto direct the emerging air in the same tangential direction relative tothe tank. As shown in FIG. 3, each deflector 94 has an inner shoulder 96which defines, with the remaining wall portion of the deflector, arestricted orifice 98 through which the air emerging from thecorresponding air conduit 92- flows to the lower curved extremity of thedeflectors. This orifice serves to increase the velocity of the emergingair. At this point, it is evident that the deflectors 94 comprise, ineffect, downwardly and tangentially directed nozzles on the air conduits92 for discharging the air emerging from the conduits downwardly andtangentially of the circle on which the conduits 9-2 lie into the tankchamber 1 4. It is significant to note that the lower extremities of thedeflectors or nozzles 94 are located in close proximity to the lowertank wall 50'.

For reasons which will appear presently, it may be desirable ornecessary to prevent backflow of fluid material through the air conduits38, 92. To this end, each conduit is equipped with a check valve 100which unseats to permit air flow through the conduits into the tankchamber 14 and seats to block reverse flow through the conduits.

The discharge conduit 20 comprises a pipe 102, on one end of which isthreaded an elbow 194 which is, in turn, threaded into the lower tankport 16. The opposite end of to pipe 102 is secured to the shutoff valve44. Adjacent the valve 44, the pipe 102 has a connection 106 connectedto the lower end of the external air conduit 38. Downstream of theshutoff valve 44, the discharge conduit 20 contains a T-fitting 108 towhich is secured an elbow 110 attached to the liquid conduit 40 throughthe valve 42.

The operation of the mixing and dispensing apparatus 10 will now bedescribed in connection with mixing and dispensing a fluent mixture ofsolid and liquid ingredients, such as a cementitious slurry containingcement, sand, and water. In this case, the liquid supply conduit 40connects to a source of water under pressure. As already noted, the airconduits 3'8, 92 connect to a source of air under pressure. Theapparatus 10 is conditioned for mixing a slurry by releasing the coverlocking means 82, opening the cover 28', and closing the discharge valve22. At this point, the water supply valve 42 and shutoff valve 44 areopened to admit Water into the tank chamber 14. When the water rises tothe correct level in the chamber, valves 42 and 44 are reclosed. Airunder pressure is now supplied to the air conduits 38, 92, and therequired number of bags of cement and sand are introduced into the tankchamber 14 through the upper tank opening 26. As noted earlier, thegrill 66 in the opening serves as a support on which each bag may berested during emptying of its contents into the chamber 14 and a meansfor regulating the dispersing the solid ingredients, i.e., cement andsand, as these ingredients are poured into the chamber. The compressedair constantly emerging from the inner air conduits 92 through thedeflectors or nozzles 94 imparts a vortical or spinning motion andagitation to the water in the chamber 14. This vortical motion andagitation of the water is beneficial for several reasons. Thus, iteffects rapid wetting and mixing of the dry ingredients with the wateras these ingredients are poured into the chamber 14. Secondly, after allof the dry ingredients have been introduced into the chamber and mixedwith the water to produce a slurry in the chamber, the tangential airjets emerging from the nozzles 94 serve to spin and agitate the slurryto a uniform mix or consistency. Finally, because of the downwardinclination of the nozzles 94, the air jets emerging therefrom tend tocontinuously sweep the bottom wall of the tank and thereby preventmaterial from accumulating on this wall, particularly in the vicinity ofthe tank port 16. As already noted, the compressed air arriving throughthe outer air conduit 38 and discharge conduit 20 enters the bottom ofthe tank chamber 14 through the tank port 16 and thereby preventsblocking of the port by the material or slurry in the tank, andparticularly by any of the solid ingredients which may tend to settle tothe bottom of the tank. Thus, the outer air conduit 38 and nozzles 94cooperate to maintain the tank port 16 open.

After the fluid material or slurry in the tank chamber 14 has beenthoroughly agitated and mixed, the manual pressure relief valve 36 isopened and the hatch cover 28 is closed and locked. In this regard, itis evident that venting of the tank chamber 14 through the pressurerelief valve 36 is desirable to permit closing of the hatch coverwithout cutting off the air supply to the air conduits 38, 92 which isessential to effect continuous agitating and mixing of the fluidmaterial or slurry in the chamber. After the hatch cover 2 8 has beensecurely locked in its closed position, the relief valve 3 6 is closedand the shutoff valve 44 is opened. The increase in air pressure withinthe chamber .14, occasioned by the air entering the chamber through theair conduits 38, 92, now becomes effective to build up pressure in thetank and expel the fluid material or slurry from the chamber through thedischarge conduit 20, as permitted by opening of the valve 22. Duringthis expulsion of the material, the air entering the chamber through thenozzles 94 continues to spin and thereby agitate and maintain thematerial in the chamber in its mixed state.

After the tank chamber 14 has been emptied, the shutoff valve 44 isclosed and the water supply valve 42 opened to direct water from thewater supply conduit 40 through the discharge conduit 20 for flushingthe latter conduit downstream of the valve 44. At this point, attentionis directed to the fact that during initial filling of the tank chamber14' with water, in the manner explained earlier, the downstream portionof the discharge conduit also fills with water which is thereafterexpelled from the conduit when the discharge valve 22 is initiallyopened, thereby effecting initial flushing of the discharge conduit. Ifdesired, the tank chamber 14 may be flushed, before or after flushing ofthe downstream portion of the discharge conduit, by closing thedischarge valve 22 and opening the water supply valve 42 and shutoffvalve 44 to admit water to the chamber. The water supply valve is thenreclosed and the discharge valve 44 reopened to permit the water todrain from the chamber. During the flushing operation, particularlyduring flushing of the tank chamber 14, compressed air may be suppliedthrough the air conduits 3 8, 92 to effect spinning of the water in andthereby thorough washing of the tank and total expulsion of the rinsewater from the tank and the discharge conduit. The hatch cover 28 isreopened to permit recarging of the tank 12 with a new batch of dryingredients after reopening the pressure relief valve 36.

While the foregoing discussion has related to operation of the presentapparatus for mixing and dispensing a fluid mixture of liquid and dryingredients, the apparatus may be used, as well, to mix and dispense theother fluid materials referred to earlier. In this regard, it will beunderstood that when mixing only dry ingredients, the liquid supplyvalve 42 will remain closed and the ingredients employed will besufliciently fine to have the requisite fluidity necessary for flowingof such ingredients through the discharge conduit.

I claim:

1. Apparatus for agitating and dispensing a fluent material comprising amixture of a solid ingredient and a liquid ingredient: comprising ahermetic tank having a chamber for containing the material and a portopening in the lower portion of said chamber, gas supply conduit meansleading from said tank for connection to a source of gas under pressureand opening to said chamber for discharging said gas into said chamberand thereby agitating the material within said chamber, a materialdischarge conduit leading from said tank port for conveying the materialfrom said chamber to a point of use, a discharge valve in said dischargeconduit for controlling material flow therethrough, vent means forselectively communicating the upper portion of said chamber toatmosphere including an upper opening in said tank through which saiddry ingredient may be introduced into said chamber, a removable hatchcover sealing said opening, means for releasably locking said cover insealing relation to said opening, whereby initially said vent means maybe opened, said discharge valve may be closed, and said gas supplyconduit means may be supplied with gas under pressure to eifectagitation of the material within said chamber, and thereafter said ventmeans may be closed, said discharge valve may be opened, and said gassupply conduit means may be supplied with gas under pressure to effectcontinued agitation of the material within said chamber and simultaneousexpulsion of the material from said chamber through said dischargeconduit by gas pressure in said chamber, and liquid supply means forintroducing said liquid ingredient into said chamber comprising a liquidsupply conduit for connection to a source of the liquid ingredient underpressure and connected to said discharge conduit between said tank anddischarge valve, and a supply valve in said liquid supply conduit.

2. Apparatus according to claim 1; wherein said gas supply conduit meanscomprises a gas supply conduit connected to said discharge conduitbetween said tank and discharge valve, whereby during initial agitationof the material in said chamber, pressurized gas enters said chamberthrough a portion of said discharge conduit and said tank port toprevent blocking of said port by the material in said chamber.

3. Apparatus according to claim 2; including a check valve in said gassupply conduit adjacent said discharge conduit for preventing backflowthrough said gas supply conduit.

4. Apparatus for agitating and dispensing a fluent material comprising amixture of a solid ingredient and a liquid ingredient: comprising ahermetic tank having a chamber for containing the material and a portopening in the lower portion of said chamber, gas supply conduit meansleading from said tank for connection to a source of gas under pressureand opening to said chamber for discharging said gas into said chamberand thereby agitating the material within said chamber, a materialdischarge conduit leading from said tank port for conveying the materialfrom said chamber to a point of use, a discharge valve in said dischargeconduit for controlling material flow therethrough, vent means forselectively communicating the upper portion of said chamber toatmosphere, whereby initially said vent means may be opened, saiddischarge valve may be closed, and said gas supply conduit means may besupplied with gas under pressure to effect agitation of the materialwithin said chamber, and thereafter said vent means may be closed, saiddischarge valve may be opened, and said gas supply conduit means may besupplied with gas under pressure to eflect continued agitation of thematerial within said chamber and simultaneous expulsion of the materialfrom said chamber through said discharge conduit by the gas pressure insaid chamber, said gas supply conduit means comprising at least oneinner gas supply conduit extending through and sealed to the wall ofsaid tank and a nozzle on the inner end of said gas supply conduitopening generally tangentially into said chamber for dischargingpressurized gas into the material within said chamber in a directiontangentially of said chamber and thereby inducing vortical motion of thematerial within said chamber, and an outer gas supply conduit connectedto said discharge conduit between said tank and discharge valve, wherebyduring initial agitation of said material in said chamber, pressurizedgas enters said chamber through a portion of said discharge conduit andsaid tank port to prevent blocking of said port by the material in saidchamber.

5. Apparatus for agitating and dispensing a fluent material comprising amixture of a solid ingredient and a liquid ingredient: comprising ahermetic tank having a chamber for containing the material and a portopening in the lower portion of said chamber, gas supply conduit meansleading from said tank for connection to a source of gas under pressureand opening to said chamber for discharging said gas into said chamberand thereby agitating the material within said chamber, a materialdischarge conduit leading from said tank port for conveying the materialfrom said chamber to a point of use, a discharge valve in said dischargeconduit for controlling material flow therethrough, vent means forselectively communicating the upper portion of said chamber toatmosphere, whereby initially said vent means may be opened, saiddischarge valve may be closed, and said gas supply conduit means may besupplied with gas under pressure to effect agitation of the materialwithin said chamber, and thereafter said vent means may be closed, saiddischarge valve may be opened, and said gas supply conduit means may besupplied with gas under pressure to effect continued agitation of thematerial within said chamber and simultaneous expulsion of the materialfrom said chamber through said discharge conduit by the gas pressure insaid chamber, said vent means comprising an upper opening in said tankthrough which the dry ingredient may be introduced into said chamber, aremmovable hatch cover sealing said opening, and means for releasablylocking said cover in sealing relation to said opening, said apparatusfurther comprising a liquid supply conduit for connection to a source ofthe liquid ingredient under pressure and connected to said dischargeconduit between said tank and discharge valve, a supply valve in saidliquid supply conduit, and said gas supply conduit means comprise atleast one inner gas supply conduit extending through and sealed to thewall of said tank and a nozzle on the inner end of said inner conduitopening tangentially into said chamber for discharging pressurized gasinto the material within said chamber in a tangential direction of saidchamber thereby inducing vortical motion of the material within saidchamber, and an outer gas supply conduit connected to said dischargeconduit between said tank and discharge valve, whereby during initialagitation of the material in said chamber, pressurized gas enters saidchamber through a portion of said discharge conduit and said tank portto prevent blocking of said port by the material in said chamber.

6. Apparatus according to claim 5, wherein said outer gas supply conduitconnects to said discharge conduit between said tank and said watersupply conduit, and said discharge conduit includes a shutoff valvebetween said water and outer gas supply conduits.

7. Apparatus according to claim 6; wherein said vent means furthercomprise a separate pressure relief vent in the upper end of said tankand a pressure relief valve closing said latter vent, and said gassupply conduits comprise check valves for perventing backflowtherethrough.

8. Apparatus for agitating and dispensing a fluent material comprising amixture of a solid ingredient and a liquid: comprising a tank having achamber provided with an inlet for the solid ingredient and a portopening in the lower portion of said chamber, a material dischargeconduit leading from said tank port for conveying the material from saidchamber to a point of use, a discharge valve in said discharge conduit,means for supplying fluid to said chamber for agitating the material insaid chamber, and a fluid supply conduit connected to said dischargeconduit between said tank and discharge valve for supplying a fluidunder pressure to said tank through said port during agitation of thematerial in said tank to prevent blocking of said port by the material.

9. Apparatus for mixing and dispensing a fluid mixture of a dryingredient and a liquid ingredient: comprising a tank having a chamber,a port opening to the lower portion of said chamber, and an opening tothe upper portion of said chamber, a liquid supply conduit forconnection to a source of the liquid ingredient under pressure andconnected to said discharge conduit between said tank and dischargevalve, a liquid supply valve in said liquid supply conduit, and ashutofl valve in said discharge conduit between said tank and liquidsupply conduit, whereby initially said supply and shutoff valves may beopened and said discharge valve may be closed to introduce the liquidingredient into said tank for mixing with the dry ingredient, andthereafter said supply and discharge valves may be opened and saidshutoff valve may be closed to direct the liquid ingredient through saiddischarge conduit for flushing the latter conduit.

References Cited UNITED STATES PATENTS 1,872,548 8/1932 Zur Lowen222-195 X 2,766,912 10/ 1956 Calamai 222195 2,792,262 5/ 1957 Hathorn.2,923,440 2/1960 Ve Horn 222l95 X 3,189,061 6/1965 Stockel et al 222-l95X WALTER SOBIN, Primary Examiner.

US. Cl. X.R.

